As a refrigerating and air-conditioning apparatus which includes a plurality of refrigeration cycles and which is capable of performing a defrosting operation while simultaneously continuing a heating operation, for example, there has been an in-vehicle air-conditioning apparatus described in Patent Literature 1. With the arrangement in which a refrigeration cycle which performs defrosting by a cooling operation and a refrigeration cycle which continues a heating operation are individually provided within the vehicle, the in-vehicle air-conditioning apparatus is able to perform a defrosting operation while simultaneously continuing a heating operation.
Furthermore, as an in-vehicle air-conditioning apparatus described in Patent Literature 2, a technique to maintain comfort by adjusting the amount of ventilation according to a vehicle occupancy, is disclosed.